Microfluidic chips, fabricated from low cost polymers, are a promising, emerging technology for synthesis and study of new molecular imaging probes. These chips can contain a variety of microcircuitry and microwells and are capable of manipulating nanoliter samples of reagents and solvents. The microfluidic chips have been designed for a multitude of applications, such as cell incubation and FDG synthesis. Adding the ability to quantify and image low amounts of radioactivity on a microfluidic chip can provide researchers with a platform to investigate new imaging probes as well as molecular processes with radiolabeled probes in a controlled in- vitro environment. The overall goal of the proposed effort is to design, build and implement a high performance position sensitive detector that can be integrated with microfluidic chips for detection and imaging of charged particles emitted by the radiolabeled probes present in the fluids circulating in these chips. High sensitivity detection of these charged particles is desired with high spatial resolution along with low minimum detectable activity.4. Project Narrative The proposed research will investigate a promising detector technology which should have a major impact in health care, in particular, in the development of a new tool for in- vitro studies of human disease models. Other areas to which this research could be of benefit are: physics research, materials studies, homeland defense, and non-destructive testing. [unreadable] [unreadable] [unreadable]